1. Field of the Invention
The present invention relates to a solar cell and a method of manufacturing the same, and more particularly, to a buried contact solar cell capable of accomplishing high efficiency and a method of manufacturing the same.
2. Description of the Related Art
A solar cell generates electric energy using solar energy. The solar cell is eco-friendly and has an infinite energy source and a long life span. The solar cell can be a silicon solar cell and a dye-sensitized solar cell.
The silicon solar cell includes a semiconductor substrate and an emitter layer that are of different conductive types so as to form a PN junction, a front electrode electrically connected to the emitter layer, and a rear electrode electrically connected to the semiconductor substrate.
The front electrode shields solar light. Accordingly, the amount of solar light which enters the solar cell is reduced by the front electrode. The loss of solar light is referred to as “shading loss.” In order to reduce the shading loss, it is preferable that the line width of the front electrode be reduced.
In order to reduce the line width of the front electrode, a buried contact solar cell in which a groove having a size corresponding to the line width of the front electrode is formed in a semiconductor substrate, and in which the front electrode is formed in the groove, has been suggested. As a method of forming the front electrode in the groove, a non-electrolytic plating method, an electrolytic plating method, a screen printing method, or an evaporation method may be used.
In the non-electrolytic plating method and the electrolytic plating method, the solution is hard to be managed, the process time is long, and productivity is low. As the line width of the groove is reduced, an undesired hole remains in the electrode, and thus a high-density electrode is difficult to be formed. In the screen printing method, there is a limit to reduction of the line width of the front electrode formed in the groove. In the evaporation method, the process is complicated, an expensive apparatus and material are required, and productivity is low.
That is, a conventional method of forming a front electrode has poor productivity. Since the front electrode is difficult to be formed in the groove with high density, failure rate is high and resistance property is low. In addition, it is substantially impossible to form the front electrode in a groove having a small line width of, for example, 50 μm. Accordingly, there is a limit to reduction of the shading loss.